3.7V To 5V 1A 2A Boost Module DIY Power Bank Mainboard Circuit Board Built In 18650 Lithium Battery Protection IC Double USB Output Over-current Over-voltage Under Voltage Protection

Features: 1. 4 level LED lights show electricity, non-working state smart automatic shutdown; 2. Built-in lithium battery protection IC, overcurrent, overvoltage, undervoltage protection; 3. Dual USB output; 4. Motherboard size: 69 x 32 x 8mm(L x W x H) Product basic parameters: Input port: Micro USB (Android port) Input requirements: 5V constant voltage power supply can be used for charging input power, the most matching charger is 5V 1A or more Output port: USB Output parameters: 5V 1A / 5V 2A Requirements for rechargeable batteries: Available battery(3.7V-4.2V polymer lithium battery): 18650 battery, mobile phone battery, flat battery, MP3 battery, can choose single cell power supply, or multiple cell parallel power supply(does not support the series). (Note: increasing capacity in parallel and increasing voltage in series, can only be used in parallel.) Can be connected in parallel with 2-6 pcs 18650 batteries... Batteries are not available: Dry cells, batteries, 1.2V rechargeable batteries, nickel hydrogen batteries, 3.2V iron lithium polymers, lithium batteries, etc. Product installation should pay attention to the following points: 1. The battery should be connected in parallel, only the voltage between 3.2-4.2V can work, 18650 flat head and polymer batteries are available; 2. The battery is connected to the motherboard, B+ stands for the positive pole, B- stands for the negative pole, if it's connected reversely will burn the motherboard; 3. The old batteries and new batteries, the batteries which model and brands are inconsistent, these battery can not be mixed. Package included: 1 x 3.7V to 5V 2A boost module